A large health study of people living near intensive piggeries in the United States, has found an increased risk of infections which are resistant to antibiotics.

Researchers at John Hopkins school of Medicine, in Baltimore, found pig manure contained methicillin resistant Staphylococcus aureus (MRSA) and an 11 per cent increase in a potentially lethal skin and tissue infection in people nearby.

In the US, about 80 per cent of antibiotics are sold to the animal industries.

Head of infectious diseases at the Austin Hospital in Melbourne, Professor Lindsay Grayson, says Australia has a better record of antibiotic use than most other countries.

"We know in the US there's heavy use of antibiotics inappropriately in agriculture.

"The message for Australia here is, we have much better controls than in the US and Europe but we're not perfect by any means.

"And we need to get onto this and tighten this area up if we're going to avoid this same scenario."

Professor Grayson, who's also Professor of Medicine at Melbourne University, worries Australia's good work in limiting antibiotic use could be undone by contaminated imports like farmed seafood. He sites the recent shipment of prawns from Vietnam contaminated with antibiotics that should never be used in animal farming.

The John Hopkins study, published in the JAMA Internal Medicine journal on September 16, mirrors a large study done recently in the Netherlands.

Professor Grayson is about to start collaboration with the Victorian Pork Association, to work on reducing antibiotic use in piggeries, through better vaccines and redesigning intensive farming practices to reduce stress on pigs.

Starting next year, his medical students will work on the project he's calling "Superbugs in the Supermarket".

John Bourke has a piggery in Victoria. He says antibiotics are not used for growth promotants in Australia.

"First thing is you look at your environment, and clean it up.

"We do post mortems and cultures to find out what problem you have, rather than write out a script for antibiotics when you don't need to."

If needed, he says, antibiotics are delivered mostly through the water, for several hours a day for a limited period.

"We're a hell of a long way ahead of our trading partners, but they're allowed to send their meat out here."